Catheter hub to nose engagement

Abstract

A catheter hub to nose engagement for securely engaging the hub of a catheter to the nose of a catheter emplacement unit is described. The attachment mechanism may be as simple as an elastic tube which provides an interference fit between the catheter hub and the nose of the emplacement unit. In an alternate embodiment the nose has a longitudinal slot to provide a split nose tip. The split nose tip is held in a separated position by the passage of a cannula therethrough and an enlarged burr end securely engages the hub and nose together. In another embodiment the nose has a longitudinally tapered nose tip and the tapered nose tip has an enlarged burr end to securely engage the hub and nose together. In a further embodiment the nose has an internal undercut in which an elastic plug is secured which is positioned between the catheter hub and nose. The elastic plus has a through hole having a diameter slightly smaller than the diameter of a catheter needle such that when the needle is inserted into the through hole the outer diameter of the elastic plug is expanded.

What is claimed is: 
     
       1. A catheter unit comprising: a. a catheter having a hub and catheter emplacement assembly having a nose and a cannula extending slidably through said nose;   b. an elastic tube provided between the catheter hub and said nose, wherein the hub and nose are securely engaged together by an interference fit between the hub and nose and also by an interference fit between the elastic tube and the nose until said cannula is moved to a position to be withdrawn from said nose.   
     
     
       2. A catheter as claimed in claim 1, wherein the nose is provided with a nose extender which is securely engaged within the elastic tube. 
     
     
       3. A catheter as claimed in claim 1, wherein the nose has a longitudinal slot to provide a split nose tip. 
     
     
       4. A catheter as claimed in claim 3, wherein the split nose tip has an enlarged burred end to securely engage the hub and nose together. 
     
     
       5. A catheter as claimed in claim 1, wherein the nose has a longitudinally tapered nose tip. 
     
     
       6. A catheter as claimed in claim 5, wherein the tapered nose tip has an enlarged burred end to securely engage the hub and nose together. 
     
     
       7. A catheter unit comprising: a. a catheter having a hub;   b. a catheter emplacement unit received within said catheter having a nose having a longitudinal slot to provide a split nose tip which engages an inner surface of said hub.   
     
     
       8. A catheter as claimed in claim 7, wherein the split nose tip has an enlarged burred end to securely engage the hub and nose together. 
     
     
       9. A catheter unit comprising a catheter having a hub and catheter emplacement assembly having a nose and a cannula extending slidably through said nose; an elastic tube provided between the catheter hub and said nose, wherein the hub and nose are securely engaged together by an interference fit between the hub and nose and also by an interference fit between the elastic tube and the nose until said cannula is moved to a position to be withdrawn from said nose; wherein the nose is provided with a nose extender which is securely engaged within the elastic tube and further wherein the nose has an internal undercut in which the nose extender is secured. 
     
     
       10. A catheter comprising; a. a catheter hub having an internal diameter, a guard having a catheter nose, and a catheter needle;   b. an elastic plug provided on said guard between the catheter hub and nose, with the elastic plug having a through hole having a diameter slightly smaller than the diameter of the catheter needle, such that when the needle is inserted into the through hole, the outer diameter of the elastic plug is expanded thereby, to securely engage the hub and nose together by an interference fit between the hub and the elastic plug.   
     
     
       11. A catheter as claimed in claim 10, wherein the nose has an internal undercut in which the elastic plug is secured. 
     
     
       12. A catheter as claimed in claim 10, wherein after the needle is withdrawn from the elastic plug through hole, the elastic plug through hole effectively closes to prevent blood from flowing through the elastic plug through hole. 
     
     
       13. A catheter as claimed in claim 12, wherein the needle gauge is 22 gauge or smaller.